Typewriting machine key



Jan. 30, 1940. Q F, BROWN '2,188,385

TYPEWRITING MACHINE KEY Filed Jan; 3l, 1938 ATTORNEYS Patented Jan. 3o, 1940 UNITED STATES PATENT vof1=111fc1i: f

Carleton .F. Brown, Syracuse, .N. Y., .assigner to.

L. C. Smith & Corona Tryllewriters, Inc., .Syracuse, N. Y., a corporation .ofNew .Kork Application January 31, 1938, fS'erial No. 187,821.1

a-claims. (cl. *1a-'zutun'y k l thefunderply'fof the tWo-plydisk, the latter ply being opaque. I

In producing lcharacter-bearing key -cards or disks of thefkindflabovedescribed it has been :found that fthe -concavity -of such disks 'varies Widely, and, since the concavity is -given to the disks to provide an agreeable contact between the-key 'and the finger of a typist, widely different degrees of concavity in different keys of -thakeyboard constitute a serious disadvantage adefeatingto a great-extentthe .purpose forwhich the'keysare provided with such cards or disks.

Thewpresent invention kprovides an improved .concave and laminated character-bearing keycard or `disk and animproved key including the same, whereby the diculties `abovementioned are'avoided .andsuch keys with disks of substanrtiallyiuniformfand constantly stable or fixed conv'cavity may be readily produced commerciallyand` economically.

Other 'features' and advantagesof the invention will appear from the following'description of .the preferredembodiment of the invention.

'I n `the accompanying drawing:

Figs 1, 2 .and 3 are fragmentary perspective lviews .showing diierent stages oct formation of a thnee-.ply laminated sheet'from which'a plurality :of character-bearing'disks are formed;

Figs. 4, 5y and. '6 are detail `vertical `sectional views .illustrating .the tier-mation of a concaved 1440 three-ply. laminated -character-bearing disk from the sheet shown in Fig. 3; v

Eign'l -is Aa sectional view on the line 1 1 of `8 showing `an improved key including a character-bearing disk of the construction shown in Figli: l

" Fig. -8y is a top plan view of the improved key Ishown in Fig. "7; and v Fig. 9 is a sectional View on the line 9--9 of Fig. 71 showing the improved key. Referring tothe invention by the drawing i1- VAlust-rating said invention as preferably exemplified and carried out, 1.0 is a transparent sheet of 'oeilulosic material -or composition such as transparent cellulose acetate, 'Il -is an opaque sheet @.55 of eellu'losic material -o'r composition such as opaque-cellulose nitrate, and lf2 `is a sheet of stiff ybut forma-ble l'or lb'endable ysheet metal such as sheet steel orv sheet brass. Preferably,. each of the sheets 2Iii) and 'il is iappreximately '5010 inch Y thick and/the sheet I-2 is' preferably .0075 inch thick. k

@ne face fof -sheet H is printed'to provide thereon aplurality or `series of type characters or key i indicia l3.for different ones of a plural-ity v`or 'series `of Aindividual `chz'iracterbearing disks, '-the i150 characters being `printed :prefer-ably Ain rowsas shown.r vThe three sheets 'thus `far described are shown'in Fig. '1.

'From these three unconnected sheets a threelply laminated sheet is Lformed, this laminated 15 -sheet 'being -shovvn inf'Fig'. 3. 'In saidflaminated sheet-the three plies or laminae lill, Hf and |12 are adherently united or Jcemented together, a suitable binding agent or cement being -used to eect adherence of sheet l2v to the imprinted 120 'race of -sheet f-I'! and a suitable transparentbind- 5ing `agent .or cement being used to effect adher- -ence #of sheet AIl) ftd the' printed face' of sheet H, heat and pressure being applied (asby `means or -aheated press) 3to eiect the joiningfof the sheets "22.5

by 4the vinterposed binding agents. Preferably, 'sheets I0 Vand /Il with the binding agent used to "bond or lunite the `same Aare-first pressed 'together under the inuence'of heat, allv in the known manner, to form the 4two-ply sheet shown in Fig. f2,- -and then this sheet and sheet |32 with a suitfable 'binding agent interposed between sheet '|2 and-"the unprinted face of sheet II. lare pressed together :under the influence Lof heat to complete the three-ply sheet shown in Fig. 3. For they.

described heating and pressing together a heated press mayibe used, :and'binding agents suitable Afor use lare Well known to those Skilled in` the art of .bonding such materials in the described man- Iier. l M4) From the flat, three-ply, laminated sheet thus formed, and `comprising the three .adherently united or bonded laminae as shown in YF'i-g. '3,

Iseveral' Acharacter-'bearing three-ply laminated and Iconcaved disks l.of ,the construction-shown lin Figs- '6, 7 and 8 are formed. .v Referring to Figs. 4, 5 and 6, l each such three-plyfeoncaved disk is formed by first punch- "ing *from the flat, laminated three-ply sheet lo-iI-x-IIZ l(asillustratedby Figs. 4 and 5) a dat, ao

circular, laminated, 'three-ply* disk IDB, Ila, l2a with the printed `character or indicia I3 appropriate for a single key appearing on said- "flat 'fdisk and preferably appreximatelyv centrally 1ojcated thereon, `andA thereafter forming thisa punched out, iiat, circular disk (shown in Fig. 5) by the application thereto of heat and pressure (as by pressing the disk between suitably shaped forming dies of a heated forming or die press) to the concaved or dished form shown in Figs. 6 to 9, in which the character or indicia I3 is visible at the concave face of the finished character-bearing disk thus formed. These formed disks may be punchedout of the yiiat sheet and formed'one at a time, or all or any part of the total number formable from the three-ply sheet may be punched out and formed at one time;

It will be observed that there is thus provided a three-ply, laminated, concaved or dished indicia-bearing card or disk for a typewriter key comprising an upper transparent lamina or ply Illb of cellulosic material or composition, a bottom or backing lamina or ply I2b of stiifbut formable sheet metal, and an intermediate opaque lamina or ply I Ib of cellulosic material, all adherently bonded or connected, and which laminated card 0r disk is one which has been molded or pressed from a flat form (preferably by application oi heat as well: as pressure) into a dished or concaved form Vin which the transparent lamina or ply is at the concave face of the finished ,disk vor card andthe character I3 is exposed to -(of known construction) of a typewriting machine, which upturned lever end is formed at its upper end with and integral and flat, horizontally disposed, substantially circular metal key base member I5.

An annular sheet metal retaining and clamping ring I6 for the character-bearing card or disk of the key embraces with its lower portion the periphery of the key base I5. This ring is formed with a pluralityofflugs I1 spaced apart around the lower edge of said ring and bent inwardly against the lower face of base I5. Two of the lugs .Il` are closely spaced to embrace the upturned end I4 of the key lever, or to engage, or

vsubstantially engage, opposite side faces of said lever end, as shown inFigs. 7 and 9.

The retaining and clamping ring I6 is formed, around itsl upper edge, with an integral inwardly extending vretaining or ,clamping ange I6a which overhangs the laminated character-bearing disk IOb, I'Ib, I2b at the periphery of theA latter and clamps said disk to a spacing washer or supporting ring I8 .which is preferably formedA of paper or paper stock; Washer or ring I8 is seated on the upper face of key base member I5 with its periphery engaged b-y the retaining ring I5 and serves to support the concaved character-bearing card or disk adjacent the periphery of the latter.

The thickness of the paper washer or ring should be such that the card or disk is securely clamped against accidental rotation, with the lowest part of the bottom of the card or disk oontacting or, preferably, slightly spaced from key base I5. The use of a paper washer or ring I8 contributes to increased friction between the sur- -faces 'clamped together, preventing accidental turning of the card or disk relatively to the key base member I5. f

`Character-bearing concaved disks orconcaved compositelaminated key cards constructed and more thin than could possibly be used'witha two- .the total thickness of4 the card change of form by any such changes in humidity and temperature as are likely to be encountered in use of a typewriting machine. The improvements also provide very thin, light, stiff and sta.- l5 ble laminated character-bearing key cards or disks.

The use of the very thin sheet metal backing ply formed of stiff but deformable sheet metal of the nature of thin sheet steel or thin sheet brass, 'l0 which can be pressed to a desired imparted form but has high resistance to change of imparted form, permitsalso the use of extremely thin disklike plies of amorphous cellulosic material, much ply card of cellulosic material. The resistancey of .the stiff sheet metal ply to deformation from ya.

given dished form imparted thereto is so' great as to entirely overcome or substantially entirely overcome any tendency of the cellulosicplies to filo curl up, atten out or otherwise deform, under the influence of internal .warping or other stresses in said cellulosic plies tending toI change the pressed shape impartedV to the laminated key card or disk. l

What Iclaim is: l l. A thin and shape retaining typewriter key card of light weight comprising a concavo-convex disk consisting of three thin andI superimposed laminae permanently adhesively bonded *'40 face to face,` the lamina at the concave side of the disk being a transparent lamina of cellulose acetate, the intermediate lamina being an opaque lamina of cellulose nitrate, the lamina at the convex side of the disk being a lamina of stiff per- T .manently f ormable sheet metal, such: asxsheet steel or sheet brass,one of said cellulose laminae through and covered by the transparent lamina,

being approxif mately .0275 inch. l

2. Atypewriter key card comprisinga concavoconvex disk having threesuperimposed laminae `permanently adhesively bonded faceto face,the

' fbeing inherently highly subjectto distortion by internal stresses, and the lamina at the convex side of the disk being of stiff permanently formable sheet material inherently substantially` free 65 vfrom internal distorting stresses and inherently highly resistant to distortion by internal stresses `in the cellulosic laminae.

3. A typewriter key card as Vclaimed in claim 2, in which'the lamina at the convex side of the.70 disk is of4 stii permanently formable sheet metal vhaving a thickness of approximately .0075 inch, .and each of the other two laminae has a thickness of approximately .010 inch. 

